Coolant system for grinding machines



Feb. 19, 1952 J. s. MATHEWS COOLANT SYSTEM FOR GRINDING MACHINES I 2 SHEETS-SHEET 1 Filed Dec. 17, 1948 INVENTOR. -61 ans. 1Y4 TAN-W8 Feb. 19, 1952 v J. 5. MATHEWS COOLANT SYSTEM FOR GRINDING MACHINES 2 SHEETS-SHEET 2 I 1 m- J Filed Dec. 17. 1948 INVENTOR. J4 at 61 mnyzws ATTORNEYS Patented Feb. 19, 1952 UNITED STATES PATENT OFFICE COOLANT SYSTEM FOR GRINDING MACHINES Jack S. Mathews, Cincinnati, Ohio, assignor to The. Cincinnati Milling Machine nati, Ohio, a. corporation of Ohio 00., Cincin- Applica'tion' December 17, 1948, Serial No. 65,828, 2 Claims. (01.51.9267,)

grinding or sharpening tools, have a relatively small grinding wheel and the work surface area and material to be removed by grinding is so comparatively small that normally the grinding operation may be effected without the generation.

of an excessive, amount of heat and thereby such operations can be performed-without the aid. of acoolant.

With the advent of harder tool materials, and

the longer grinding time requiredto remove the necessary amount of material, an. excessive amount of heat is generated which is detrimental, and this slows down the grinding time because of intermittentstops in order to.prevent the generation of too much heat.

Furthermore, such wheels, beingsmall, run at relatively high speeds. and are not very well guarded whereby the application of coolant to such machines becomes. a difficult matter,.first to prevent splashing of the coolant, and secondly, such machines are not designed or equipped in the first instance to handle coolant.

It is, therefore, an object of this invention to improve the construction of such machines as cutter grinders and' tool grinders so that wet grinding operations may beperformed thereon.

Another object of this invention is to provide an improved efiicient and compact system for applying coolant to a grinding wheel.

A further object of this invention is to-provide an improved method for applying coolant to grinding wheels.

Other objects and-advantagesof the present invention should be readily apparent by reference to the following specification, considered" in conjunction with the accompanying drawings forming a part thereof, and it'is'to be understood that any modificationsmay be made in the exact structural details there shown and described,

within the-scope of the appended claims, with.

out departing from or exceeding the spirit of the invention.

In the drawings in which. like referenceinume'rals indicate like or similar parts:

Figure 1 is a general assembly of the mechanism comprising this invention.

Figure 2 is a section on the line 22 of Figure 1.

Figure 3 is a view partly in section on the line 3-3 of Figure 1.

Figures land 5 are detail views of the guard rings.

Referring now toFigure 2 of the drawings, the reference numeral [-0 indicates the tapered end of a spindle ll, forming part of a cutter grinder or like machine, upon which suitable grinding wheels may be mounted. The spindle is suitably journaled in a spindle housing [2 and actuated by conventional form of power means. For

clearance purposes of this invention, an adapter I3 is preferably attached to the spindle II, and

has a reduced end l4 upon which a grinding wheel.l5 is mounted and secured by a locki'ngnut It for rotation by the spindle. f'he'wheel I5 is a cone-shaped wheel and has agrinding face H.

In general,:the improved-method of applying the-coolant to the grinding wheel in accordance with this invention is to supply the coolant in a -fine stream to the face of the wheel IT and to utilize the centrifugal force of the wheel to throw the coolant across. the grinding face of the wheel to its outer periphery and then to provide a suctionmeans adjacent the outer periphery of the wheel to draw off the coolant vapor as fast as it is thrownout and thereby eliminate the necessity for. providing collecting grooves, channels, andguards on the work supporting table and other. parts of the machine.

A-self-contained unit is provided for supplying and withdrawingv the coolant. Such a unit is shown in Figure 1 of 'the drawings and comprises a tank unit [8 in which is formed a general reservoir l9 containing a supply of coolant, and within this reservoir is mounted a pump 20 connected to be driven by a motor 2| located on the cover'22 of the tank. A delivery pipe 23 extends fromthe pump and is connected to a reducing nipple 24 mounted in part of the housing-25 of an exhaustfan 26. A smaller pipe 21 is connected to the nipple inside of the housing 25 and thisipipe extendsthrough the center of an exhaust pipe 28 which extends to the spindle housing [2. The exhaust pipe 28 is connected to a 'T 29: which is mounted on top of the spindle 45 housing I2 as shown in Figure 1'. A plug 30 is threadedin the T to whichthe pipe 21. is connected inside of the T and in axial alignment with a valve 3! threaded in the outerend of the plug. Alflexible' pipeiorspout 32 is connected to the valve, and this spout may be bent in such form and in such relation to the wheel as to deliver coolant to the face of the wheel as shown in Figure 2. It is thus obvious that by means of the valve the coolant may be turned on or off.

A housing 33, as shown on Figure 2, is provided to act as a guard for the grinding wheel and also is provided with a receiving chamber 39 for receiving the expended coolant from the grinding wheel. The housing 33 is supported on the end of a pair of rods 34 which project from the wheel housing i2 in which they are suitably fastened, and set screws 35 are threaded in the housing for securing the same to the rods 34. By loosening the set screws, the housing may be shifted alon the rods 34, and this is convenient when it is necessary to change the grinding wheel as well as for various adjusting purposes.

The housing 33 includes a closure plate or inner wall 36 which is contoured to fit the back contour of the grinding wheel and is provided with a lip 31 which cooperates with a lip 38 to form a narrow annular exhaust duct adjacent the periphery of the wheel. The chamber 39 in the housing is connected to the T 29 and thereby to the exhaust pipe 28 which extends to the inlet 25 of the exhaust fan 26. The fan is driven by a suitable motor 4!, the fan and motor being mounted on the cover 22 of the tank.

It will be noted that the housing 33 is adjusted on the rods 34 in such a manner that the end of the lips just clear the end face of the wheel, thus permitting access of tools to the face of the wheel for grinding purposes. A spray guard, indicated generally by the reference numeral 4 I, is mounted on a groove 42 formed on the end of the housing 33 and this guard comprises a pair of telescoping bands 43 and 44 which are shown in detail in Figures 4 and 5. The band 43 has a cut-away portion 45 which extends substantially halfway around the band, and the band 44 has a similar cut-away portion 46 which extend substantially halfway around the band. Each band is split as at 41 in Figure 4, and 48 in Figure 5. The band 43 is intended to fit within the band 44 and a screw 49 shown in Figure 1 is adapted to tighten the bands around the periphery of the housing 33. It will be noted that the cut-away portion of the band 43 is on the upper half -circle while the cutaway portion of the band 44 is in the lower half of the circle so that by rotating one band with respect to the other, an opening 50 may be provided at one side of the wheel through which a tool to be sharpened may be passed into engagement with the face of the grinding wheel. These bands thus prevent spray from flying and confine it so as to be drawn by suction through the annular orifice into the chamber 39.

In the operation of the device, the suction fan is started which creates a vacuum in the chamber 39 of the wheel housing and thereby a strong induction of air through the annular opening between the lips 31 and 38. Thus, as coolant is supplied across the face of the wheel it is propelled by centrifugal force across the incoming stream of air and carried thereby into the chamber 39 and duct 28 to the fan 26 where it is expelled through the opening shown in Figure 3 to the reservoir IS. The air being lighter in weight, passes around the fan and i expelled through opening 52 to the interior of the tank and permitted to escape through opening 53 to the atmosphere.

What is claimed is:

1. In a wet grinding attachment for a dry grinding machine having a spindle support, a spindle journaled therein, and a grinding wheel detachably connected to the end of said spindle, the combination of a self-contained portable coolant tank and pump unit, a power driven suction fan mounted on said tank and having an exhaust outlet communicating with said tank, a flexible suction pipe having one end connected to the inlet of said fan, a grinding wheel housing connected to the other end of said suction pipe, a coolant delivery pipe connected at one endto said pump and extending through and supported by said suction pipe and terminating at said housing in a delivery nozzle, said housing including a first wall having a bore fitting said spindle and shaped to enclose one side and the periphery of said grinding wheel, and an outer wall connected to said first wall to form an annular suction chamber around said spindle, said walls terminating in spaced relation to form a narrow annular suction orifice at the periphery of the grinding wheel, and means to detachably connect said housing to said spindle support with the mouth of said orifice adjacent to the peripheral edge of the grinding face of the grinding wheel.

2. In a wet grinding attachment for a dry grinding machine having a spindle support, a spindle journaled therein and a grinding wheel attached to the end of said spindle, the combination of a housing having an outside wall in which is formed a bore fitting said spindle whereby the housing may be detachably mounted on the support between the grinding wheel and said support, means to detachably connect said housing to said support for adjustment parallel to the axis of said spindle, an inner wall member shaped to enclose the periphery of the wheel fitted within said housing and attached to said outer wall adjacent said spindle to form an annular chamber within said housing, said wall terminating in closely spaced relation to the periphery of the wheel to form a narrow annular orifice around the wheel, and means to evacuate said chamber to develop a suctional force at the periphery of the wheel.

JACK S. MATHEWS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Germany Aug. 8, 1900 

